High pH Levels
Regulating pH is one of the most important aspects of pool care and it should be maintained in the range 7.2 – 7.6.
High pH will also reduce the effectiveness of chlorine based sanitisers.
To reduce pH
pH Resistant to Movement
This can cause cloudiness, excessive scaling and residues in the pool.
Probable cause – High total alkalinity
Total alkalinity is a measure of the alkaline materials (mainly bicarbonates) in the pool water and should be maintained in the range 80 – 150mg/l (ppm). Having sufficient total alkalinity prevents sudden pH fluctuation (‘bounce’) but an excessively high total alkalinity will make the pH resistant to change and the water will then become what is described as over buffered. High total alkalinity makes it difficult to adjust the pH as any correcting chemicals will have their effect taken up (buffered) by the total alkalinity. The management of pH will become relatively easy once the total alkalinity level is within the range of 80 – 150mg/l (ppm).
High total alkalinity can arise from a number of causes:
To lower the total alkalinity